The present invention relates to disposable diapers of open-type adapted to be worn with body waste absorbing and retaining pad carried thereon.
There have been known disposable diapers of open-type defining a front waist region, a rear waist region and a crotch region extending between these waist regions. The diapers comprise a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core interposed between these sheets and extending between the front and rear waist region. A pair of end flaps extend in a transverse direction of the diaper outside longitudinally opposite ends of the core and a pair of side flaps extend outside transversely opposite side edges of the core. The diaper is adapted to be worn with a body waste care pad laid on the topsheet. One of such diapers are disclosed, for example, in Japanese Unexamined Patent Application Publication No. 2003-116910 (hereinafter referred to as “Reference”).
In the diaper of disclosed in Reference, the crotch region is formed in its transverse middle with a depressed zone in which the pad is to be laid. The depressed zone is formed from the top- and backsheets except the core and has an elliptical shape which is relatively long in the longitudinal direction. The depressed zone is provided along its peripheral edge with a circularly extending stretchable elastic member contractably attached thereto. A pair of tape fasteners is attached to the side flaps in the rear waist region, respectively, and extends in the transverse direction. Contractile force of the elastic member functions to reduce an area of the depressed zone and thereby to further depress this zone in a thickness direction of the diaper so that the pad can be securely laid in the depressed zone. Consequently, it is unlikely that the pad might be out of alignment during use of the diaper. To wear the diaper disclosed in Reference, the pad is laid in the depressed zone, then the side flaps in the rear waist region are placed upon outsides of the respective side flaps in the front waist region, and free ends of the respective tape fasteners are fastened to the outer surface of the front waist region while the tape fasteners are pulled outward in the transverse direction to connect the front and rear waist regions with each other. Upon connection of the front and rear waist regions, the diaper is formed with a waist-hole and a pair of leg-holes.
In the case of the diaper disclosed in Reference, the side flaps in the rear waist region are pulled outward in the transverse direction as the free ends of the respective tape fasteners are fastened to the outer surface of the front waist region to wear the diaper. Once the front and rear waist regions having been connected with each other by means of the tape fasteners around the wearer's body, these side flaps in the front and rear waist regions pull one another to be strained outward in the transverse direction. While the side flaps continue to be strained outward in the transverse direction in the course of wearing the diaper as well as during use of the diaper, a tensile force exerted upon these side flaps is not transmitted to the elliptical depressed zone so efficiently to pull the depressed zone outward in the transverse direction and thereby to keep the depressed zone strained outward in the transverse direction. Consequently, the depressed zone remains slack down in the thickness direction of the diaper in the course of wearing the diaper as well as during use of the diaper, making it impossible for this known diaper to press the pad laid in the depressed zone against the wearer's skin. So far as the pad is not in close contact with the wearer's skin, a clearance is left between the pad and the wearer's skin and body waste can not be reliably absorbed and retained by the pad.